Heating and cooling pads are commonly used to treat a variety of bodily injuries and ailments with a non-ambient temperature fluid. For example, a cold pack is frequently used in the treatment of sprains and similar injuries to inhibit swelling in the region of the injury. Hot water bottles are also frequently used to reduce pain and promote healing.
A number of devices are known in the art for applying non-ambient temperature fluids in the treatment of injuries and other body ailments. The patents to Mason et al., U.S. Pat. No. 5,241,951; and Hardy, U.S. Pat. No. 3,674,034, disclose pads in which a non-ambient temperature fluid is circulated. The patents to Saggers, U.S. Pat. No. 4,753,242; Pagden, U.S. Pat. No. 4,781,193; Faghri, U.S. Pat. No. 5,269,369; and Gilbert, U.S. Pat. No. 3,606,890, disclose devices that use a circulating fluid for therapeutic purposes, and which conform to the patient's head. However, none of the aforementioned patents provide a pad that circulates a temperature-adjusting fluid proximate the orbital, frontal, nasal, and temporal regions of the head and, therefore, to the anatomical structures therein.
Likewise, it is known in the art to provide temperature therapy to the face with a mask that covers a person's eyes. The "EENT stay-dry ice pack" shown on page 201 of the 1993 Baxter Medical-Surgical catalog shows an ice pack that is worn over a person's eyes to apply cold therapy to the facial tissues. The "EENT" device holds cooling fluid in a vinyl inner bag in the manner of an ice pack shaped and worn like a mask. The "EENT" device does not provide a pad that circulates a temperature adjusting fluid through channels proximate certain specific blood vessels and structures in the orbital, frontal, nasal, and temporal regions of the head. The "EENT" device also appears to be substantially planar and does not have a molded, anatomically conforming shape. The "EENT" device also does not provide a means for regulating the temperature of the fluid contained therein.
The orbital, frontal, nasal, and temporal regions of the head are of particular interest to ophthalmologists, neurologists, ear, nose and throat specialists, internists, and psychiatrists. Heating pads may be of use to ophthalmologists to treat certain inflammations of the eye, particularly in the eyelids and lacrimal glands, which need local heat in addition to other therapeutic measures. Neurologists may use heating and cooling pads in the treatment of headaches having a vascular component. Heating and cooling pads may be of use to ear, nose, and throat specialists in the treatment of sinusitis, which is an inflammation of the sinuses. Local heat next to the sinuses improves blood circulation and the delivery of antibiotics and anti-inflammatories as well as reduces pain. Internists may use cooling pads in the management of fever, especially in circumstances where the patient cannot take anti-pyretics. Cooling pads may be the only method of controlling such fever, which if untreated could lead to febrile seizures.
The application of local heat may also be of interest to psychiatrists to provide a non-pharmacological treatment for clinical depression and other biopsychiatric disorders. It is known that abnormalities in the levels and metabolism of certain brain chemicals known as neurotransmitters can cause a host of psychiatric disorders. For example, recent research shows that 95% of the people who commit suicide have biochemical abnormalities in their brains. One neurotransmitter that has recently been the subject of extensive research is serotonin. Serotonin is intricately linked to the orbital cortex, which is the part of the brain that sits just above the eyes and affects mood and impulse control. Nerve cells manufacture, release, and absorb serotonin in quick bursts that ripple throughout the cerebrum. Low levels of serotonin are associated with clinical depression; therefore, serotonin is the target of antidepressant drugs, such as Prozac, which keep it active in the brain longer than usual. In one study of 20 suicide victims, it was shown that in almost every case, not enough serotonin had reached the orbital cortex of the brain. Time, Nov. 28, 1994, pp. 65-66.
The supraorbital, supratrochlear, angular, lateral nasal, external nasal, infraorbital, and ophthalmic veins all converge in the orbital cavity and eventually lead to the cavernous sinus. These vessels can be regarded and utilized as natural "heating tubes" that carry warmed blood inward proximate to the orbital cortex and the frontal cortex. The other structures of key interest are the orbital portion of the frontal bone and the frontal and ethmoid sinuses, which have blood capillaries of their own, and which are proximate to the brain.
Marcelo Enrique Lopez-Claros, M.D., postulates that increasing the blood flow to the orbital cortex will stimulate the metabolism of neurons, thereby resulting in an increased availability of serotonin. This increased level of serotonin may be achieved in at least two ways: (1) by cautious, measured increases in the temperature of the blood supply to the neurons, thereby stimulating their metabolism and increasing the natural production of serotonin; and (2) increasing the blood supply to the orbital cortex, the frontal cortex, and the temporal cortex by achieving selective vasodilatation (opening) of the vessels leading thereto, thereby delivering a larger quantity of natural chemicals such as hormones and a variety of medications with antidepressant and antianxiety properties with known serotonergic activity to these key target areas of the brain. Additionally, with such an increase in drug availability in these areas of the brain, lower dosages and therefore lower plasma concentrations of certain drugs may be needed to achieve a therapeutic effect. The benefits of using a lower dosage of a drug include lower medication expenses and fewer side effects.